clarification about whitespace
On the mailing list it was observed that some proposed changes to the definitions of whitespace might be overbroad and make for inconvenient (and possibly incompatible) parsers.
The original change was itself motivated by incompatible implementations, so it does seem that there is something worth clarifying here.
I've just opened !33 (merged) to revert the standing changes (which had been introduced in the earlier epoch by !6 (merged)), but i'm opening this issue to keep track of the outstanding problem with the documentation.